OBJECTIVE: To develop and implement comprehensive and detailed long-range plans of research directed toward improving prevention, diagnosis, and treatment of large bowel cancer. APPROACH: The project, through the combined efforts of the Directorate, Working Cadre and consultant scientist groups, has planned and activated a multidisciplinary approach to large bowel cancer aimed at reducing the incidence, mortality, and morbidity of this disease. Through the research grants mechanism, investigators in various laboratories and institutions across the country, and in selected foreign institutions, are conducting research programs on the biology and control of large bowel cancer. These research programs are within the following broad scientific areas: (1) Carcinogenesis and Epidemiology, (2) Cell Kinetics and Molecular Control of Cell Proliferation and Differentiation and Molecular Genetics, (3) Early Diagnosis, Prevention and Human Genetics, (4) Experimental-Clinical Pharmacology, (5) Immunobiology, (6) Pathological Classification and Correlation with Prognosis, and (7) Clinical Research Treatment including Chemotherapy, Immunotherapy, Radiation Therapy, Surgery and Multimodal Therapy. The National Large Bowel Cancer Project encourages interested investigators to submit to the Headquarters Office applications for research grants-in-aid related to the previously mentioned research categories. Applications are then reviewed by consulting scientists and members of the Working Cadre. Following processing and evaluation of grant requests, the recommendations of the Working Cadre are referred to the Division of Cancer Research Resources and Centers of the National Cancer Institute for final adjudication and funding.